Performance Tuning -To find the execution time for Select Statement

Question

Hi,
There is a program that takes 10 hrs to execute. I need tune its performance. The program is basically reading few tables like KNA1,ANLA,ANLU,ADRC etc and updates to Custom table. I did my analysis and found few performance techniques for ABAP coding.
Now my problem is, to get this object approved I need to submit the execution statistics to client.I checked both ST05 and SE30. I heard of a Tcode where we can execute a select statement and note its time, then modify and find its improved Performance. Can anybody suggest me on this.
Thanks,
Rajani.

Answer 1

Hi,
This is documentation regarding performance analysis. Hope this will be useful
It is a general practice to use           Select  *  from <database>…     This statement populates all the values of the structure in the database.
The effect is many fold:-
•     It increases the time to retrieve data from database
•     There is large amount of unused data in memory
•     It increases the processing time from work area or internal tables
It is always a good practice to retrieve only the required fields. Always use the syntax      Select f1  f2  …  fn  from <database>…      
e.g.     Do not use the following statement:-
     Data: i_mara like mara occurs 0 with header line.
     Data: i_marc like marc occurs 0 with header line.
     Select * from mara
          Into table i_mara
          Where matnr in s_matnr.
     Select * from marc
          Into table i_marc
          For all entries in i_mara
          Where matnr eq i_mara-matnr.
     Instead use the following statement:-
                                   Data: begin of i_mara occurs 0,
                                        Matnr like mara-matnr,
                                              End of i_mara.
     Data: begin of i_marc occurs 0,
          Matnr like marc-matnr,
                                        Werks like marc-werks,
                                             End of i_marc.
     Select matnr from mara
          Into table i_mara
          Where matnr in s_matnr.